Simulation of the Decontamination Efficiency of PET Recycling Processes based on Solid‐state Polycondensation

The recollection rates for postconsumer poly(ethylene terephthalate) (PET) bottles and the recycling capacities are increasing year by year. The postconsumer PET bottles were recycled either to fibres or to new packaging applications. For packaging applications, the so‐called super‐clean recycling technologies are applied to decontaminate the postconsumer PET pellets. Most of these processes are based on solid‐state polycondensation processes. Because experimental determination of the cleaning efficiency is a time‐consuming and expensive procedure, it would be useful to predict the cleaning efficiencies, e.g. for process development and optimization. Within this study, the decontamination kinetics of a PET super‐clean recycling process based on solid‐state polycondensation was determined. From the decontamination kinetics, the diffusion coefficients were calculated. By use of the diffusion coefficients, the decontamination kinetics was simulated using migration modelling approaches for spherical pellets. The result of this study shows that the decontamination of PET pellets in solid‐state polycondensation processes follows Fickian laws. The diffusion coefficients of the investigated migrants are not influenced by vacuum or inert gas process conditions. The diffusion equations used in commercially available software packages for migration calculation can be used for the simulation of the decontamination efficiencies of PET recycling processes. Copyright © 2012 John Wiley & Sons, Ltd.     

Investigation of antimony,cobalt, and acetaldehyde migration into the drinking water in Turkey

Polyethylene terephthalate (PET) is a widely used material for the packaging of drinking water. The development of this research arises from the demand of a popular Turkish drinking water company, which has reported odour problems in their PET bottled products. Acetaldehyde, cobalt, and antimony contents were determined in bottled water of different volumes (0.5, 1.5, and 5 L), PET bottles, plastic blue closures, and preform material by gas chromatography mass spectrometry (GC‐MS) and inductively coupled plasma mass spectrometry (ICP‐MS). Antimony, cobalt, and acetaldehyde migration into the drinking water (PET bottled) was tracked for every 2 months through a year. Migration of these compounds rose with increased storage time at 20°C. The highest amounts of migrated compounds were observed in 0.5 L (smallest) of PET bottles. All migration results were found to be under the migration limit at the end of storage period. In addition to these findings, nonintentionally added substances (NIASs) analyses were performed by headspace (HS)/GC‐MS. Odour‐active compounds were identified using the library database. Off‐odours in the drinking water were due to the migration of various compounds such as acetaldehyde and other NIASs from PET bottle into the drinking water. In addition, acetaldehyde amounts were ranged from 0 to 140 μg/L in all drinking waters, and some acetaldehyde values were above the taste threshold of 15 μg/L.     

Quantification of the Sorption Behavior of Polyethylene Terephthalate Polymer versus PET/PA Polymer Blends towards Organic Compounds

Polyethylene terephthalate (PET) bottles are widely used for beverages. Oxygen‐sensitive beverages, however, often require the use of barrier materials or oxygen‐scavenging additives incorporated into the PET material, which is in most cases polyamide (PA). As a consequence, small amounts of polyamide are entering the PET bottle‐to‐bottle recycling feedstream. Aim of the study was therefore the determination of the sorption behavior of bottles made of different PET/PA blends in comparison with a PET reference. As a result, PET test bottles containing blended PA amounts of up to 1000 ppm do not show a sorption behavior for the investigated model compounds, which is different from pure PET material. Therefore, polyamide impurities in the recycling streams coming from polyamide barrier bottles will not lead to a different sorption/remigration behavior as pure PET bottles. Consequently, evaluations of PET recycling processes will still be valid for feedstream materials containing such small amounts of polyamide from barrier bottles. On the other hand, the introduction of 8% of polyamide decreases significantly the sorption of organic compounds into the bottle wall. Copyright © 2011 John Wiley & Sons, Ltd.     

Kalte Normaldruck‐Jetplasmen zur lokalen Oberflächenbehandlung

Cold non‐thermal plasma jets for local surface treatment under normal pressure Plasmas at normal pressure are of considerable interest for surface technology because the industrial application requires no vacuum devices. Among other approaches, cold non‐thermal plasma jets represent an emerging technique to generate plasmas at normal pressure with attractive advantages. They allow ambient process temperatures and require only moderate operating voltages (1.5‐2.5 kV). They offer the advantage that the treated surfaces are not placed between the electrodes thus favoring local treatment of non flat, structured 3D surfaces. Moreover, the dimension of the sources is scalable and their integration into automated processes is simple. A capacitively coupled version (27.12 MHz) of a cold plasma jet suitable for surface treatment at atmospheric pressure is presented along with its plasma physical and technical properties and a series of successful applications, including plasma activation of surfaces for increasing printability, adhesion control, surface cleaning, microfluidics, decontamination, its use in plasmamedicine and for deposition of thin SiO₂ films as protective coatings. The device allows the operation with rare gases (e.g. Ar) and reactive gases as N₂, air or admixtures of silicon‐containing compounds.     

Effects of weight reduction of packaging material on the mechanical performance of PET bottles for cooking oil

This study compares and evaluates the mechanical performance of two types of PET bottle of different nominal weights but identical design and filled with 900 ml vegetable cooking oil. The air in the headspace of all the bottles was replaced with liquid or gaseous nitrogen upon conclusion of the filling operation and immediately before capping. Two different closures, with an internal or external tamper‐evident feature, were used on the 20 g bottles. The 27 g bottle was closed exclusively with the closure fitted with an external seal. The 20 g PET bottles prior to capping were either flushed with gaseous nitrogen or pressurized with liquid nitrogen. The air contained in the headspace of the 27 g bottle was removed by injection of gaseous nitrogen only. Corrugated fibreboard cases containing 20 bottles each were submitted to a vibration test and all the components of the packaging system were subsequently evaluated with respect to important mechanical properties, such as stacking strength, drop impact strength and package integrity. The results show that the closure with external seal provided considerably better protection against leakage. Also tests conducted with stacks of five corrugated cases each and arranged onto two pallets placed one upon the other demonstrated that reducing total bottle weight by 26% is viable in terms of mechanical performance. On the other hand, the use of pressurized liquid nitrogen was found to be unnecessary. Copyright © 2000 John Wiley & Sons, Ltd.     

Beidseitige Innen‐ und Außenbeschichtung von PET‐Getränkeflaschen

Double‐sided interior and exterior coating of PET beverage bottles Plasma‐enhanced methods for the interior coating of PET beverage bottles have already been put into practice in the industry. Thereby the achieved barrier properties are limited due to defects in the coating, which emerge during the layer growth and allow a higher permeability. One possible way to improve barrier properties is the double‐sided coating. The implementation of the concept in form of a demonstrator plant is presented. By means of optical emission spectroscopy (OES) as a very versatile and easy to use method for the surveillance of industrial plasma processes, the influence of the gas composition on the plasma homogeneity and barrier properties of the coating is demonstrated. Permeation measurements are carried out, showing the potential of the combined coating process for the deposition of effective coatings.     

荧光照射下PET阻隔瓶对杀菌乳风味的保护研究

目的 研究分析添加质量分数为8%的阻光色油的PET瓶（简称阻光8%PET瓶）包装对杀菌乳风味物质组成和含量的影响,为杀菌乳保质期的延长提供数据支撑。方法 模拟超市货架光照情况,以纯PET瓶和阻光8%PET瓶包装做对比,分析不同贮存期杀菌乳感官风味指标变化及特征风味物质组成及含量变化。结果 相对纯PET瓶杀菌乳,阻光8%PET瓶杀菌乳,光照3、7 d后两样品关键感官特性指标（奶香气、奶腥味、异味强度）及整体喜好度平均值均表现出显著性差异（P<0.05）,阻光8%PET瓶杀菌乳的奶香气、整体喜好度评价均优于纯PET瓶杀菌乳的,奶腥味、异味强度均低于纯PET瓶杀菌乳的。经特征风味化合物分析,醛类化合物对杀菌乳异常风味贡献最大,酸类、酮类、醇类物质贡献较小。结论 阻光8%PET瓶包装能有效延缓光照31 d贮存期杀菌乳产品醛类物质的种类和含量的迅速增加,能一定程度减少部分酸类、酮类、醇类物质的增加,从而减少异常风味,提高产品的喜好度,可一定程度延长杀菌乳的货架期。     

On‐going solutions to environmental issues in plastic packaging

Recently, the consumption of polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) resins as packaging materials has been declining in the face of various environmental problems they pose. To replace PVC containers, the use of PET bottles and A‐PET containers is on the increase, but PVDC resins are still in wide use as gas‐barrier materials. For gas‐barrier purposes, however, ethylene vinyl alcohol co‐polymer (EVOH) films, polyvinyl alcohol (PVA)‐coated polypropylene films, and MX nylon or silica‐ or alumina‐coated PET films are becoming mainstream. The weight reduction of plastic bottles is considered to play an important role in tackling the waste disposal problem. Recently, a new type of stretch‐blow moulding system has been developed, which is effective in reducing the weight of PET bottles. This system is called COSMOS (complete stretch‐blow moulding system) or the two‐blow system. COSMOS PET bottles are now used to hold carbonated drinks containing fruit juice or lactic acid. Copyright © 2001 John Wiley & Sons, Ltd.     

Mikrowellen‐Plasmabrenner bei Atmosphärendruck

Microwave Plasma Torch at Atmospheric Pressure The development of the microwave plasma torch shows that a combination of two resonators is targeting for a reliable ignition under atmospheric pressure and stable continuous operation at high power conditions. An adapted gas management with jacket flow and good mixing can be produced by the coaxial design. The spectroscopic investigation of the torch gives information about the spatial temperature distribution in the plasma. The distribution of the OH‐rotation‐vibration band is observed in the line of sight with a high spectroscopic resolution. In an air plasma a constant core gas temperature of 3600 K is determined. It is independent of the outside parameters, like microwave power or gas flow. Only the plasma volume adapts, in order to keep the energy content constant.     

PET瓶在热灌装饮料中的应用

通过PET的分子结构、物理/化学特性来说明影响PET瓶品质的物理、化学因素;通过PET瓶的生产工艺流程及热灌装PET的吹瓶方法/过程、及影响因素来说明PET瓶品质问题的产生原因及其解决方法;通过PET瓶在热灌装线的使用过程来说明影响PET热灌装饮料包装品质的因素及其解决方法;从而为PET瓶在热灌装线的使用提供了较有借鉴意义的资料.     

Quality of orange juice in barrier packaging material

The vitamin C content and the colour of orange juice made from concentrate were measured during 9 months of storage at 20°C either under artificial light or in darkness. The packaging materials used were glass, standard monolayer polyethylene terephthalate (PET) and multilayer PET (PET/nylon and oxygen scavenger/PET) containers. In this experiment, all bottles were sealed with aluminium foil in order to avoid any cap effect. The results showed that in plastic packaging materials, the loss of vitamin C was related to the oxygen permeability, and that glass provided the best preservation of ascorbic acid. No statistical difference (p < 0.05) was revealed between the vitamin C content in the juice stored under artificial light or in darkness, whatever the packaging used. The modification of colour was studied with the L, a* and b* values during storage at 20°C under artificial light. L and b* decreased, revealing a reduction of lightness and yellow colour of the juice, whereas a* increased, due to the formation of brown pigments. This change in colour was partly related to the oxygen permeability of the packaging used. The losses of aroma compounds by permeation through the bottle (PET) and the cap (high‐density polyethylene, HDPE) have also been investigated. The results showed that permeation mainly took place through the cap. The use of a multilayer cap [HDPE with internal barrier layer of low‐density polyethylene (LDPE)/EvOH/LDPE] considerably limited the permeation of the aroma compounds studied, whatever the PET bottle used. Copyright © 2007 John Wiley & Sons, Ltd.     

Plasmachemisches Ätzen und Beschichten bei Atmosphärendruck

Atmospheric pressure plasma‐chemical etching and deposition. Application in crystalline silicon photovoltaics. For industrial processing of wafer based crystalline silicon solar cells a variety of different technologies are applied. The combination of these requires a complex wafer handling; increasing not only investment costs, but also the risk of wafer breakage. Application of plasma technologies offers the possibility to manufacture crystalline silicon solar cells without any wet chemical or vacuum processes. At Fraunhofer IWS all etching steps necessary for the production of solar cells and the deposition of silicon nitride as passivation and anti‐reflection coating were demonstrated successfully using atmospheric pressure plasma technologies.     

Contact angle analysis of low-temperature cyclonic atmospheric pressure plasma modified polyethylene terephthalate

Polyethylene terephthalate (PET) films are modified by cyclonic atmospheric pressure plasma. The experimentally measured gas phase temperature was around 30 °C to 90 °C, indicating that this cyclonic atmospheric pressure plasma can treat polymers without unfavorable thermal effects. The surface properties of cyclonic atmospheric pressure plasma-treated PET films were examined by the static contact angle measurements. The influences of plasma conditions such as treatment time, plasma power, nozzle distance, and gas flow rate on the PET surface properties were studied. It was found that such cyclonic atmospheric pressure plasma is very effective in PET surface modification, the reduced water contact angle was observed from 74° to less than 37° with only 10 s plasma treatment. The chemical composition of the PET films was analyzed by X-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) was used to study the changes in PET surface feature of the polymer surfaces due to plasma treatment. The photoemission plasma species in the continuous cyclone atmospheric pressure plasma was identified by optical emission spectroscopy (OES). From OES analysis, the plasma modification efficiency can be attributed to the interaction of oxygen-based plasma species in the plasma with PET surface. In this study, it shows a novel way for large scale polymeric surface modification by continuous cyclone atmospheric pressure plasma processing.     

Long‐time Performance of Bottles Made of PET Blended with Various Concentrations of Oxygen Scavenger Additive Stored at Different Temperatures

Blending of poly(ethylene terephthalate) (PET) with oxygen scavenger additives is a way to reduce ingress of oxygen into PET bottles made of these blends. The objective is to reduce oxidation of packaged beverages and oils. However, few studies were performed about the long‐time influence of temperature on PET bottles with oxygen scavenger additives. Such knowledge is relevant for the development of accelerated tests. In this study, the influence of temperature on oxygen permeation of PET bottles with the oxygen scavenger additives MXD6 or Oxyclear® was examined. PET bottles made of blends of PET with 2, 5 and 8 wt.?% MXD6, respectively, or with 2 wt.?% Oxyclear® were filled with deoxygenated water. The bottles were stored at 5, 23, 38 and 55 °C up to 5 years. Oxygen partial pressure of the water in the bottles was measured regularly. As expected, oxygen partial pressure increased earlier at higher temperature because of faster exhaustion of the oxygen scavenger. Oxygen partial pressure of water in PET bottles with 8 wt.?% MXD6 was below 10 mbar even after 5 years storage time at 5 and 23 °C. Oxygen absorption capacity of activated MXD6 was at least 76 mg/g. This study shows that PET bottles with oxygen scavengers are able to reduce the oxygen ingress for several years, even at elevated temperatures. Copyright © 2017 John Wiley & Sons, Ltd.     

药用玻璃包装自动装盒系统设计与实现

目的 针对现阶段药用玻璃包装产业升级对数字化、自动化、智能化的设备的迫切需求，提出一种药用玻璃瓶（西林瓶、安瓿瓶、口服液制剂瓶等）自动装盒方法，以降低劳动强度，提高产品质量。方法 以安瓿瓶为例，在充分分析具体需求的基础上，借助计算机辅助设计技术和仿真技术，采用“自顶向下”的设计方法，完成系统三维模型机械设计和运动仿真。利用PLC工业控制技术，建立能够兼容不同规格产品的生产线的控制模型，实现系统智能控制，并完成样机的试制。结果 在国内几家大型药用玻璃包装生产企业成功应用后，所研制的药用玻璃瓶自动装盒系统能够有效减少因传统装盒方法对瓶身造成的划伤和污染，包装人员成本减少了40%，产品合格率提高了5%。结论 所研制的药用玻璃瓶自动装盒系统可显著提高产品的质量、降低劳动成本，加快了行业自动化、智能化进程。     

Corona Discharge Plasma Jet Inactivates Food‐borne Pathogens Adsorbed onto Packaging Material Surfaces

The potentiality of corona discharge plasma jet (CDPJ) for disinfection of food packaging materials, including glass, polyethylene, polypropylene, nylon and paper foil, was evaluated. CDPJ was generated using a high voltage (20 kV) pulsed DC power source, at 1.5 A current and 58 kHz frequency. The separation distance between plasma electrode and sample plate during the treatment was 25 mm. Upon treating food pathogens‐loaded packaging materials by the plasma, 4.5–5.0 log/cm² reductions (99.999%) in viable cell counts of Escherichia coli O157:H7 and Staphylococcus aureus were observed in 120 s. Another tested pathogen Salmonella Typhimurium was inactivated by 3.0 log/cm² units. The patterns of inactivation of pathogens are fitted well to Weibull tail model. Compared to untreated controls, the CDPJ‐treated packaging materials exhibited insignificant (p > 0.05) changes in the optical characteristics, tensile strengths, surface temperatures and strain‐induced deformation. Therefore, the most common food packaging materials harboring bacterial pathogens could be disinfected by the CDPJ without compromising physicomechanical properties of materials. Copyright © 2017 John Wiley & Sons, Ltd.     

Wirtschaftliche Anwendung von Mikrowellen‐Plasmen vom mittleren bis Atmosphärendruck. Economic utilisation of microwave excited plasma in medium to atmospheric pressure

An overview on the potential of medium to atmospheric pressure processes will be given and discussed in context to production applications. The introduction of the medium to atmospheric pressure plasma source is a huge progress and a valuable, attractive tool. The plasma source bases on the concept of cy lindrical r esonator with annu lar s lots (CYRANNUS®). High process speed and reliability are the most important facts for technical applications. Parameters as gas/flow dynamic can be controlled and lead to further improvements of equipment and process design. The CYRANNUS® plasma is used in down‐stream configuration for several applications such as glass films on polymer substrate to reduce oxygen permeation, protective coatings against corrosion or wear and hydrophilic or hydrophobic surface properties. Also etching or cleaning can be done easily because of arbitrary process gas in the plasma source. The advantage of medium pressure is higher supply of reactive species and improved transportation of reaction products. Various processes with plasma surface interaction are discussed from physical and technical viewpoint as plasma enhanced CVD, plasma polymerisation on metal or polymer substrates. Using the advantages of medium pressure plasma processes consequently leads to new design of equipment and material flow. In‐line/on‐line treatment of 3‐D material becomes most efficient and enables competitive plasma processes for mass productions. For diamond deposition a larger size of the plasma at high pressure processes are essential for a device with best economics.     

Free-stretch-blow investigation of poly(ethylene terephthalate) over a large process window

This paper highlights for the first time a full comprehension of the deformation procedure during the injection stretch blow moulding (ISBM) process of poly(ethylene terephthalate) (PET) containers, namely thin-walled rigid bottles. The processes required to form PET bottles are complicated and extensive; any development in understanding the nature of material deformation can potentially improve the bottle optimisation process. Removing the bottle mould and performing free-stretch-blow (FSB) experiments revealed insight into the bottle forming characteristics at various preform temperatures and blowing rates. Process outputs cavity pressure and stretch-rod force were recorded using at instrumented stretch-rod and preform surface strain mapping was determined using a combination of a unique patterning procedure and high speed stereoscopic digital image correlation. The unprecedented experimental analysis reveals that the deformation behaviour varies considerably with contrasting process input parameters. Investigation into the effect on deformation mode, strain rate and final bottle shape provide a basis for full understanding of the process optimisation and therefore how the process inputs may aid development of the preferred optimised container.     

Plasmachemische Gasphasenabscheidung und Plasmaätzen bei Atmosphärendruck

Plasma enhanced Chemical Vapour Deposition and plasma etching at atmospheric pressure Plasma processes are applied for a variety of surface modifications. Examples are, e.g. coatings to achieve an improved corrosion and scratch protection, or surface cleaning and texturising. Since these processes, however, usually take place in vacuum, they are unfortunately not applicable for large area industrial use. Plasma enhanced CVD processes at atmospheric pressure enable the deposition of functional coatings on components and semi‐finished parts with in a continuous air‐to‐air process without the use of expensive vacuum systems. By their integration into in‐line production processes the substrate handling and the coating costs are definitely reduced. A thermal plasma source, basing on a linearly extended DC arc discharge at atmospheric pressure, has been tested for the deposition of silicon nitride at substrate temperature of less than 300° in a continuous PECVD process. Furthermore this source has been tested for plasma‐chemical etching and texturising of silicon as well.     

Plasmagestützte Flascheninnenbeschichtung

Application of substrate biasing for plasma enhanced inner coating of plastic bottles to improve barrier properties The article summarizes the results of a research project aiming at the improvement of the barrier performance of plastic beverage bottles by means of plasma enhanced barrier coatings. A pilot plant for the biased barrier coating of PET‐bottles was designed and successfully commissioned within the scope of the investigations. In the process, two excitation types are examined: the so‐called in‐plasma process and a single‐sided plasmaline process for the deposition of barrier coatings. Advantages as well as draw backs of both processes are investigated with respect to an industrial implementation. As a result, improvement of the barrier performance by adjustment of the substrate bias is estimated by a factor of 2‐3. At the same time, substantial challenges for the realization of the processes as well as possible approaches for their solution are identified with the support of gas flow simulations.